non metal
noble gas
alkali metal
alkaline earth metal
metalloid
halogen
metal
transition metal
post transition metal
lanthanoid
actinides
1

H

Hydrogen
1.00794(4)

2

He

Helium
4.002602(2)

3

Li

Lithium
6.941(2)

4

Be

Beryllium
9.012182(3)

5

B

Boron
10.811(7)

6

C

Carbon
12.0107(8)

7

N

Nitrogen
14.0067(2)

8

O

Oxygen
15.9994(3)

9

F

Fluorine
18.9984032(5)

10

Ne

Neon
20.1797(6)

11

Na

Sodium
22.98976928(2)

12

Mg

Magnesium
24.3050(6)

13

Al

Aluminum
26.9815386(8)

14

Si

Silicon
28.0855(3)

15

P

Phosphorus
30.973762(2)

16

S

Sulfur
32.065(5)

17

Cl

Chlorine
35.453(2)

18

Ar

Argon
39.948(1)

19

K

Potassium
39.0983(1)

20

Ca

Calcium
40.078(4)

21

Sc

Scandium
44.955912(6)

22

Ti

Titanium
47.867(1)

23

V

Vanadium
50.9415(1)

24

Cr

Chromium
51.9961(6)

25

Mn

Manganese
54.938045(5)

26

Fe

Iron
55.845(2)

27

Co

Cobalt
58.933195(5)

28

Ni

Nickel
58.6934(4)

29

Cu

Copper
63.546(3)

30

Zn

Zinc
65.38(2)

31

Ga

Gallium
69.723(1)

32

Ge

Germanium
72.64(1)

33

As

Arsenic
74.92160(2)

34

Se

Selenium
78.96(3)

35

Br

Bromine
79.904(1)

36

Kr

Krypton
83.798(2)

37

Rb

Rubidium
85.4678(3)

38

Sr

Strontium
87.62(1)

39

Y

Yttrium
88.90585(2)

40

Zr

Zirconium
91.224(2)

41

Nb

Niobium
92.90638(2)

42

Mo

Molybdenum
95.96(2)

43

Tc

Technetium
98

44

Ru

Ruthenium
101.07(2)

45

Rh

Rhodium
102.90550(2)

46

Pd

Palladium
106.42(1)

47

Ag

Silver
107.8682(2)

48

Cd

Cadmium
112.411(8)

49

In

Indium
114.818(3)

50

Sn

Tin
118.710(7)

51

Sb

Antimony
121.760(1)

52

Te

Tellurium
127.60(3)

53

I

Iodine
126.90447(3)

54

Xe

Xenon
131.293(6)

55

Cs

Caesium
132.9054519(2)

56

Ba

Barium
137.327(7)


lanthanides


57

La

Lanthanum
138.90547(7)

58

Ce

Cerium
140.116(1)

59

Pr

Praseodymium
140.90765(2)

60

Nd

Neodymium
144.242(3)

61

Pm

Promethium
145

62

Sm

Samarium
150.36(2)

63

Eu

Europium
151.964(1)

64

Gd

Gadolinium
157.25(3)

65

Tb

Terbium
158.92535(2)

66

Dy

Dysprosium
162.500(1)

67

Ho

Holmium
164.93032(2)

68

Er

Erbium
167.259(3)

69

Tm

Thulium
168.93421(2)

70

Yb

Ytterbium
173.054(5)

71

Lu

Lutetium
174.9668(1)

72

Hf

Hafnium
178.49(2)

73

Ta

Tantalum
180.94788(2)

74

W

Tungsten
183.84(1)

75

Re

Rhenium
186.207(1)

76

Os

Osmium
190.23(3)

77

Ir

Iridium
192.217(3)

78

Pt

Platinum
195.084(9)

79

Au

Gold
196.966569(4)

80

Hg

Mercury
200.59(2)

81

Tl

Thallium
204.3833(2)

82

Pb

Lead
207.2(1)

83

Bi

Bismuth
208.98040(1)

84

Po

Polonium
209

85

At

Astatine
210

86

Rn

Radon
222

87

Fr

Francium
223

88

Ra

Radium
226


actinides


89

Ac

Actinium
227

90

Th

Thorium
232.03806(2)

91

Pa

Protactinium
231.03588(2)

92

U

Uranium
238.02891(3)

93

Np

Neptunium
237

94

Pu

Plutonium
244

95

Am

Americium
243

96

Cm

Curium
247

97

Bk

Berkelium
247

98

Cf

Californium
251

99

Es

Einsteinium
252

100

Fm

Fermium
257

101

Md

Mendelevium
258

102

No

Nobelium
259

103

Lr

Lawrencium
262

104

Rf

Rutherfordium
267

105

Db

Dubnium
268

106

Sg

Seaborgium
271

107

Bh

Bohrium
272

108

Hs

Hassium
270

109

Mt

Meitnerium
276

110

Ds

Darmstadtium
281

111

Rg

Roentgenium
280

112

Cn

Copernicium
285

113

Nh

Nihonium
284

114

Fl

Flerovium
289

115

Mc

Moscovium
288

116

Lv

Livermorium
293

117

Ts

Tennessine
294

118

Og

Oganesson
294

1 Hydrogen - nonmetal

Hydrogen is both the lightest element and the most plentiful element in the universe. In terms of atoms over 90% of elements are hydrogen. This makes up to around 75% of the mass of visible matter.

Because it’s so light or, to put it another way, because earth’s gravity is so weak it’s rare to find it on earth in it’s pure form. It tends to float away into space. However when bound with oxygen its far more dense and fills our world in the form of water or H₂O.

There are 2 isotopes of hydrogen, deuterium H2 and tritium H3.

These isotopes can be use to create hydrogen bombs. These use nuclear fission to create energy to start a fusion reaction. The H bomb could be 1000 times more powerful than the atomic bomb dropped on Hiroshima.

Melts at 14°K or -259°C
Boils at 20°K or -253°C

Discovered: 1766

Atomic mass: 1.00794(4)
Atomic radius: 37
Density: 8.99e-05 g/cm³

Configuration: 1s1

Electron Affinity: -73

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2 Helium - noble gas

The second lightest and second most plentiful element in the universe but rare on earth. In fact was first discovered in the sun using spectroscopes. Hydrogen and helium make up 98% of all elements in the universe.

As a noble gas it’s the second least reactive of all elements after neon. It is the only element that has no solid form at any temperature. In it’s liquid form has the lowest boiling point of any element at -269°C. That’s just 4° above absolute zero.

But it’s a couple of degrees below this that things get really interesting. At 2°K helium turns into a superfluid. Superfluids have no viscosity and behave in peculiar ways divorced from our everyday experience. Superfluid helium can flow up the side of a vessel or even flow straight through the sides and bottom of a glass container. When stirred the vortices can keep spinning indefinitely.

Some radioactive elements decay into alpha particles. An alpha particle is a helium nucleus.

Melts at °K or
Boils at 4.22°K or -268.78°C

Discovered: 1868

Atomic mass: 4.002602(2)
Atomic radius: 32
Density: 0.0001785 g/cm³

Configuration: 1s2

Electron Affinity: 0

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3 Lithium - alkali metal

The lightest metal that’s so soft can be cut with a knife. It will float on water but also reacts with water releasing hydrogen and can catch fire. It also reacts with nitrogen in the air and turns black.

These it’s used for batteries of every conceivable kind from flashlight to laptops, from phones to cars. Lithium carbonate is used to treat bipolar disorder.

Melts at 454°K or 181°C
Boils at 1615°K or 1342°C

Discovered: 1817

Atomic mass: 6.941(2)
Atomic radius: 134
Density: 0.535 g/cm³

Configuration: [He] 2s1

Electron Affinity: -60

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4 Beryllium - alkaline earth metal

The metal is steel-gray in color, very light, with one of the highest melting points of the light metals.

Its modulus of elasticity is a third higher than that of steel. Beryllium has high thermal conductivity, is nonmagnetic, and resists attack by concentrated nitric acid.

Beryllium resists oxidation in air at ordinary temperatures. The metal has a high permeability to x-radiation. When bombarded by alpha particles, it yields neutrons in the ratio of approximately 30 million neutrons per million alpha particles. Beryllium and its compounds are toxic and should not be tasted to verify the metal’s sweetness.

Melts at 1560°K or 1287°C
Boils at 2743°K or 2470°C

Discovered: 1798

Atomic mass: 9.012182(3)
Atomic radius: 90
Density: 1.848 g/cm³

Configuration: [He] 2s2

Electron Affinity: 0

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5 Boron - metalloid

Although elemental boron is not considered to be a poison, assimilation of boron compounds has a cumulative toxic effect.

Recent research on boron has been aimed at creating boron bucky balls. Bucky balls have been created with with carbon but not with another element.

Melts at 2348°K or 2075°C
Boils at 4273°K or 4000°C

Discovered: 1807

Atomic mass: 10.811(7)
Atomic radius: 82
Density: 2.46 g/cm³

Configuration: [He] 2s2 2p1

Electron Affinity: -27

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6 Carbon - nonmetal

Carbon is the fourth most abundant element in the universe (hydrogen, helium, and oxygen are found in higher amounts, by mass). It is the 15th most abundant element in the Earth’s crust.

Carbon is a nonmetal that can bond with itself and many other chemical elements, forming over ten million compounds. Because it forms more compounds than any other element, it is sometimes called the “King of the Elements.”

Elemental carbon can take the form of one of the hardest substances (diamond) or one of the softest (graphite).

Carbon black was the first pigment used for tattooing. Ötzi the Iceman has carbon tattoos that endured through his life and are still visible 5200 years later.

The amount of carbon on Earth is fairly constant. It is transformed from one form to another via the carbon cycle. In the carbon cycle, photosynthetic plants take carbon from air or seawater and convert it into glucose and other organic compounds via the Calvin cycle of photosynthesis. Animals eat some of the biomass and exhale carbon dioxide, returning carbon to the atmosphere.

Melts at 3823°K or 3550°C
Boils at 4300°K or 4027°C

Discovered: antiquity

Atomic mass: 12.0107(8)
Atomic radius: 77
Density: 2.26 g/cm³

Configuration: [He] 2s2 2p2

Electron Affinity: -154

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7 Nitrogen - nonmetal

Nitrogen (aka Azote) is the most abundant gas in the Earth’s atmosphere making up 78% of the Earth’s air.

Nitrogen bonds between 2 nitrogen atoms are the strongest bonds between any two atoms that are the same.

There are 16 known isotopes of nitrogen ranging from N-10 to N-25. There are two stable isotopes: N-14 and N-15. N-14 is the most common isotope accounting for 99.6% of natural nitrogen.

Melts at 63°K or -210°C
Boils at 77°K or -196°C

Discovered: 1772

Atomic mass: 14.0067(2)
Atomic radius: 75
Density: 0.001251 g/cm³

Configuration: [He] 2s2 2p3

Electron Affinity: -7

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8 Oxygen - nonmetal

In 1775–80, French chemist Antoine-Laurent Lavoisier, with remarkable insight, interpreted the role of oxygen in respiration as well as combustion, discarding the phlogiston theory, which had been accepted up to that time; he noted its tendency to form acids by combining with many different substances and accordingly named the element oxygen (oxygène) from the Greek words for “acid former.”

Approximately two thirds of the human body and nine tenths of the mass of water is oxygen.

The usual form of oxygen near the Earth’s surface is dioxygen, O2. Dioxygen or gaseous oxygen is the form of the element used by living organisms for respiration. Trioxygen or ozone (O3) is also gaseous at ordinary temperatures and pressure. This form is highly reactive. Oxygen also forms tetraoxygen, O4, in one of the six phases of solid oxygen. There is also a metallic form of solid oxygen.

Melts at 55°K or -218°C
Boils at 90°K or -183°C

Discovered: 1604 or 1774

Atomic mass: 15.9994(3)
Atomic radius: 73
Density: 0.001429 g/cm³

Configuration: [He] 2s2 2p4

Electron Affinity: -141

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9 Fluorine - halogen

Fluorine is the most electronegative element. Fluorine has an electronegativity of 3.98 on the Pauling Electronegativity Scale and a valence of 1. A fluorine atom needs one electron to fill its outer electron shell and achieve stability, which is why free fluorine exists as the F- ion.

Fluorine was suspected to be an element as early as 1810 but wasn’t successfully isolated until 1886. Many chemists trying to isolate the element would be blinded or even killed by the violent reactions that generally accompany fluorine gas.

Melts at 54°K or -219°C
Boils at 85°K or -188°C

Discovered: 1886

Atomic mass: 18.9984032(5)
Atomic radius: 71
Density: 0.001696 g/cm³

Configuration: [He] 2s2 2p5

Electron Affinity: -328

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10 Neon - noble gas

Neon is famous for signs, but it’s also used in lasers, TVs, and as a refrigerant.

Neon is a rare gaseous element. It is present in the atmosphere to the extent of 1 part per 65,000 of air.

Neon is the least reactive element there is and there are no known compounds.

Melts at 25°K or -248°C
Boils at 27°K or -246°C

Discovered: 1898

Atomic mass: 20.1797(6)
Atomic radius: 69
Density: 0.0009 g/cm³

Configuration: [He] 2s2 2p6

Electron Affinity: 0

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11 Sodium - alkali metal

The pure metal is stored in oil or kerosene because it spontaneously ignites in water. Sodium metal also floats on water.

At room temperature, sodium metal is soft enough that you can cut it with a butter knife.

There is only one stable isotope of sodium: 23Na.

It’s found in the sun and many other stars. It is the sixth most abundant element on Earth, comprising about 2.6% of the earth’s crust. It is the most abundant alkali metal.

Sodium is an essential element in animal nutrition. In humans, sodium is important for maintaining fluid balance in the cells and throughout the body, while the electric potential maintained by sodium ions is critical for nerve function.

Melts at 371°K or 98°C
Boils at 1156°K or 883°C

Discovered: 1807

Atomic mass: 22.98976928(2)
Atomic radius: 154
Density: 0.968 g/cm³

Configuration: [Ne] 3s1

Electron Affinity: 53

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12 Magnesium - alkaline earth metal

Magnesium is one-third lighter than aluminium, silvery-white, and relatively tough. The metal tarnishes slightly in air. Finely divided magnesium ignites upon heating in air, burning with a bright white flame.

All known living cells require magnesium for nucleic acid chemistry.

Magnesium is the 10th most abundant element in the human body. In humans, over 300 enzymes use magnesium as a catalyst.

The average adult human body contains 22 to 26 grams of magnesium, mostly in the skeleton and skeletal muscles. Magnesium deficiency (hypomagnesemia) is common and occurs in 2.5 to 15% of the population. Causes include low calcium consumption, antacid therapy, and loss from the kidneys or gastrointestinal tract. Chronic magnesium deficiency is associated with hypertension, type 2 diabetes, and metabolic syndrome.

Foods rich in magnesium include nuts, cereals, cocoa beans, green leafy vegetables, and some spices.

Magnesium is the 8th most abundant element in the earth’s crust. While it is not found in its elemental form in nature, it is available in minerals including magnesite and dolomite.

Melts at 923°K or 650°C
Boils at 1363°K or 1090°C

Discovered: 1808

Atomic mass: 24.3050(6)
Atomic radius: 130
Density: 1.738 g/cm³

Configuration: [Ne] 3s2

Electron Affinity: 0

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13 Aluminum - metal

Aluminum is one of the most abundant metals on earth similar to magnesium and sodium and even greater than iron. However aluminium is usually found in a compound and bound up with clay and so it takes a lot of energy (electricity) to separate it. This is why it’s well worth preserving and recycling.

When it was first discovered and separated it was considered extremely valuable, more than silver or gold.

Aluminum has a very thin coating of aluminium oxide on it’s surface which protects it and prevents it from reacting with things.

Melts at 933°K or 660°C
Boils at 2792°K or 2519°C

Discovered: antiquity

Atomic mass: 26.9815386(8)
Atomic radius: 118
Density: 2.7 g/cm³

Configuration: [Ne] 3s2 3p1

Electron Affinity: -43

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14 Silicon - metalloid

Silicon is the second most abundant element in the Earth’s crust after oxygen - about 28% by mass. Sand is one source of silicon in the form of silicon dioxide.

Like copper and iron silicon has a time period named after it. We are now living in the Silicon Age, also known as the Digital Age, because of the large impact elemental silicon has on the world economy. Very highly purified elemental silicon is essential to the transistors and integrated circuit chips used in most modern technology such as smartphones and other computers. Silicon is a semiconductor which means it’s electrical conductivity increases with temperature.

Many places in the world important for semiconductor industry have acquired nicknames using ‘silicon’. By far the most famous is Silicon Valley in California but there are many more. In the UK alone there is Silicon Fen (Cambridge), Silicon Roundabout (London), Silicon Glen (Scotland) and Silicon Gorge (Bristol).

Despite the use of silicon for semiconductors these only use 5% of the total amount of silicon produced each year. The rest is used in glass, brick, silicon polymers and solar panels. Silicon is used in silicone breast implants. Silicones are polymers containing silicon, oxygen and carbon.

Melts at 1687°K or 1414°C
Boils at 3173°K or 2900°C

Discovered: 1854

Atomic mass: 28.0855(3)
Atomic radius: 111
Density: 2.33 g/cm³

Configuration: [Ne] 3s2 3p2

Electron Affinity: -134

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15 Phosphorus - nonmetal

Phosphorus is the first element discovered with a date and name. It was discovered in 1669 by alchemist Hennig Brandt who was trying to find the philosopher’s stone: the magical substance that could to turn base metals into gold. Brandt boiled 5,500 litres of well aged urine down to 120 grams of a waxy white solid that glowed in the dark: white phosphorus. This had to be kept in water to avoid bursting into flames in the air. It wasn’t recognized as an element until 1777 by Lavoisier.

White phosphorus is one allotrope of phosphorus. The others are red and black phosphorus.

Phosphorus both toxic and essential for life: 1% of human bodyweight is made up of calcium phosphate stored in bones. It’s also present in both DNA and RNA.

Phosphorus was used to create match heads, the production of which lead to poisoning of those manufacturing the matches. Later the white phosphorus that was used was replaced with red phosphorus. Phosphorus was also used in incendiary devices in WWII. The fires created were hard to put out.

Phosphates are used as fertilizers in agriculture. Organophosphates are used as weedkillers and also in highly toxic nerve agents.

Melts at 317°K or 44°C
Boils at 554°K or 281°C

Discovered: 1669

Atomic mass: 30.973762(2)
Atomic radius: 106
Density: 1.823 g/cm³

Configuration: [Ne] 3s2 3p3

Electron Affinity: -72

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16 Sulfur - nonmetal

Sulfur was known as brimstone in the Bible and ancient times. It’s famed for bad smells but this in its hydrogen sulfide forms. Ammonium Sulfide is used in stink bombs. Sulfuric acid is the most widely used chemical in industry.

Although well known in ancient times it was Antoine Lavoisier who proved it was an element in 1772.

Melts at 388°K or 115°C
Boils at 718°K or 445°C

Discovered: antiquity

Atomic mass: 32.065(5)
Atomic radius: 102
Density: 1.96 g/cm³

Configuration: [Ne] 3s2 3p4

Electron Affinity: -200

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17 Chlorine - halogen

Melts at 172°K or -101°C
Boils at 239°K or -34°C

Discovered: 1774

Atomic mass: 35.453(2)
Atomic radius: 99
Density: 0.003214 g/cm³

Configuration: [Ne] 3s2 3p5

Electron Affinity: -349

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18 Argon - noble gas

The symbol for argon used to be just A but was changed in 1957 to Ar by the International Union of Pure and Applied Chemistry (IUPAC).

Argon is the most abundant noble gas. It accounts for about 0.94% of the Earth’s atmosphere and about 1.6% of the Martian atmosphere. The thin atmosphere of the planet Mercury is about 70% argon. Not counting water vapor, argon is the third most abundant gas in the Earth’s atmosphere, after nitrogen and oxygen. It is produced from fractional distillation of liquid air. In all cases, the most abundant isotope of argon on the planets is Ar-40.

Most of the argon on Earth comes from the radioactive decay of potassium-40 into argon-40. Over 99% of the argon on earth consists of the isotope Ar-40. In the rest of the universe the most abundant type is Ar-36.

No stable compounds are known at room temperature and pressure, although argon fluorohydride (HArF) has been observed at temperatures below 17K.

Melts at 84°K or -189°C
Boils at 87°K or -186°C

Discovered: 1894

Atomic mass: 39.948(1)
Atomic radius: 97
Density: 0.001784 g/cm³

Configuration: [Ne] 3s2 3p6

Electron Affinity: 0

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19 Potassium - alkali metal

The only metal that is lighter than potassium is lithium. The silvery white metal is soft (easily cut with a knife). The metal must be stored in a mineral oil, such as kerosene, as it oxidizes rapidly in air and catches fire spontaneously when exposed to water. Its decomposition in water evolves hydrogen. Potassium and its salts will color flames violet.

Melts at 337°K or 64°C
Boils at 1032°K or 759°C

Discovered: 1807

Atomic mass: 39.0983(1)
Atomic radius: 196
Density: 0.856 g/cm³

Configuration: [Ar] 4s1

Electron Affinity: -48

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20 Calcium - alkaline earth metal

Melts at 1115°K or 842°C
Boils at 1757°K or 1484°C

Discovered: antiquity

Atomic mass: 40.078(4)
Atomic radius: 174
Density: 1.55 g/cm³

Configuration: [Ar] 4s2

Electron Affinity: -2

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21 Scandium - transition metal

Melts at 1814°K or 1541°C
Boils at 3103°K or 2830°C

Discovered: 1876

Atomic mass: 44.955912(6)
Atomic radius: 144
Density: 2.985 g/cm³

Configuration: [Ar] 3d1 4s2

Electron Affinity: -18

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22 Titanium - transition metal

Melts at 1941°K or 1668°C
Boils at 3560°K or 3287°C

Discovered: 1791

Atomic mass: 47.867(1)
Atomic radius: 136
Density: 4.507 g/cm³

Configuration: [Ar] 3d2 4s2

Electron Affinity: -8

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23 Vanadium - transition metal

Melts at 2183°K or 1910°C
Boils at 3680°K or 3407°C

Discovered: 1803

Atomic mass: 50.9415(1)
Atomic radius: 125
Density: 6.11 g/cm³

Configuration: [Ar] 3d3 4s2

Electron Affinity: -51

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24 Chromium - transition metal

Melts at 2180°K or 1907°C
Boils at 2944°K or 2671°C

Discovered: antiquity

Atomic mass: 51.9961(6)
Atomic radius: 127
Density: 7.14 g/cm³

Configuration: [Ar] 3d5 4s1

Electron Affinity: -64

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25 Manganese - transition metal

Melts at 1519°K or 1246°C
Boils at 2334°K or 2061°C

Discovered: 1774

Atomic mass: 54.938045(5)
Atomic radius: 139
Density: 7.47 g/cm³

Configuration: [Ar] 3d5 4s2

Electron Affinity: 0

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26 Iron - transition metal

Melts at 1811°K or 1538°C
Boils at 3134°K or 2861°C

Discovered: antiquity

Atomic mass: 55.845(2)
Atomic radius: 125
Density: 7.874 g/cm³

Configuration: [Ar] 3d6 4s2

Electron Affinity: -16

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27 Cobalt - transition metal

Cobalt was used as a blue pigment to replace the extremely expensive ultramarine.

Cobalt is part of vitamin B12 which is used by every cell in the body.

Cobalt can be added to nuclear weapons to make the payload more deadly, a cobalt bomb. When nuclear fission takes place the cobalt is turned into a radioactive isotope, cobalt-60. This has a half life of 5.27 years and so can contaminate an area with the fallout for a decade or more.

Melts at 1768°K or 1495°C
Boils at 3200°K or 2927°C

Discovered: antiquity

Atomic mass: 58.933195(5)
Atomic radius: 126
Density: 8.9 g/cm³

Configuration: [Ar] 3d7 4s2

Electron Affinity: -64

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28 Nickel - transition metal

Melts at 1728°K or 1455°C
Boils at 3186°K or 2913°C

Discovered: 1751

Atomic mass: 58.6934(4)
Atomic radius: 121
Density: 8.908 g/cm³

Configuration: [Ar] 3d8 4s2

Electron Affinity: -112

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29 Copper - transition metal

Copper is one of only two elements that have a period time named after them. The Copper age preceded and is less well known than the Iron Age and because copper is a relatively soft metal the Copper Age soon drifted into the Bronze Age when people learned to add tin or other metals to the copper to turn it into the harder alloy bronze. The earliest evidence of copper use is from around 6500 BCE.

Copper is one of only four coloured elements the others being gold, osmium and caesium. However it oxidizes after prolonged exposure to the air and turns green. This is copper carbonate also known as verdigris.

In the modern world copper is a widely used element. As a great conductor of electricity its used in all manner of electronic and electrical devices. It’s also used in the wiring of our homes a buildings. It’s mailability and resistance to corrosion means it’s now widely used in buildings for water supplies.

Copper is the main metal in the alloy bronze and is used in making many famous sculptures. Though some, like the huge Statue of Liberty (1886) in New York, is made from pure copper. This was chosen over bronze or stone due to its lower cost, weight, and ease of transportation.

Copper’s symbol, Cu, comes from the Latin for copper cuprum. The ancients associated copper with the planet Venus.

Melts at 1358°K or 1085°C
Boils at 3200°K or 2927°C

Discovered: in antiquity

Atomic mass: 63.546(3)
Atomic radius: 138
Density: 8.92 g/cm³

Configuration: [Ar] 3d10 4s1

Electron Affinity: -118

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30 Zinc - transition metal

Melts at 693°K or 420°C
Boils at 1180°K or 907°C

Discovered: 1746

Atomic mass: 65.38(2)
Atomic radius: 131
Density: 7.14 g/cm³

Configuration: [Ar] 3d10 4s2

Electron Affinity: 0

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31 Gallium - metal

Melts at 303°K or 30°C
Boils at 2477°K or 2204°C

Discovered: 1875

Atomic mass: 69.723(1)
Atomic radius: 126
Density: 5.904 g/cm³

Configuration: [Ar] 3d10 4s2 4p1

Electron Affinity: -29

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32 Germanium - metalloid

Melts at 1211°K or 938°C
Boils at 3093°K or 2820°C

Discovered: 1886

Atomic mass: 72.64(1)
Atomic radius: 122
Density: 5.323 g/cm³

Configuration: [Ar] 3d10 4s2 4p2

Electron Affinity: -119

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33 Arsenic - metalloid

A classic poison.

It’s estimated that 2.1 million people in the U.S. and as many as 140 million people worldwide drink arsenic-contaminated water. In terms of public health risks, arsenic may well be the worst element of all.

While deadly, arsenic was used to treat syphilis because it was vastly superior to the old treatment, which involved mercury. In the modern era, arsenic compounds show promise in treating leukemia.

Melts at 1090°K or 817°C
Boils at 887°K or 614°C

Discovered: antiquity

Atomic mass: 74.92160(2)
Atomic radius: 119
Density: 5.727 g/cm³

Configuration: [Ar] 3d10 4s2 4p3

Electron Affinity: -78

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34 Selenium - nonmetal

Melts at 494°K or 221°C
Boils at 958°K or 685°C

Discovered: 1817

Atomic mass: 78.96(3)
Atomic radius: 116
Density: 4.819 g/cm³

Configuration: [Ar] 3d10 4s2 4p4

Electron Affinity: -195

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35 Bromine - halogen

Bromine is one of only two elements that is liquid at room temperature, the other being mercury. It’s a reddish brown colour that tends to evaporate into suffocating brown fumes. It smells bad and its name means ‘stench of the he-goats’. Bromine is diatomic, Br², and highly toxic and corrosive to the skin.

With 7 electrons in its outer shell bromine happily gains an extra electron creating Br- known as bromide. Bromides is not toxic in small amounts.

Melts at 266°K or -7°C
Boils at 332°K or 59°C

Discovered: 1826

Atomic mass: 79.904(1)
Atomic radius: 114
Density: 3.12 g/cm³

Configuration: [Ar] 3d10 4s2 4p5

Electron Affinity: -325

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36 Krypton - noble gas

Melts at 116°K or -157°C
Boils at 120°K or -153°C

Discovered: 1898

Atomic mass: 83.798(2)
Atomic radius: 110
Density: 0.00375 g/cm³

Configuration: [Ar] 3d10 4s2 4p6

Electron Affinity: 0

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37 Rubidium - alkali metal

Melts at 312°K or 39°C
Boils at 961°K or 688°C

Discovered: 1861

Atomic mass: 85.4678(3)
Atomic radius: 211
Density: 1.532 g/cm³

Configuration: [Kr] 5s1

Electron Affinity: -47

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38 Strontium - alkaline earth metal

The only element on the Periodic table named after somewhere in Britain. Strontian is in Scotland.

When nuclear weapons testing took place in the 1950s and 60s a fallout byproduct was a radioactive form of strontium, strontium-90. Because strontium is in the same group as calcium, strontium could be taken up by the bones in people in place of the calcium that was supposed to be there.

Melts at 1050°K or 777°C
Boils at 1655°K or 1382°C

Discovered: 1790

Atomic mass: 87.62(1)
Atomic radius: 192
Density: 2.63 g/cm³

Configuration: [Kr] 5s2

Electron Affinity: -5

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39 Yttrium - transition metal

Yttrium is the first of 4 elements named after the Swedish town of Ytterby. The other 3, all lanthanides, are terbium Tb, erbium Er and ytterbium Yb.

Ytterby is famous for having the most amount of elements discovered in the world. In addition to the above there was also scandium Sc, holmium Ho, thulium Tm, gadolinium Gd and tantalum Ta.

Melts at 1799°K or 1526°C
Boils at 3618°K or 3345°C

Discovered: 1794

Atomic mass: 88.90585(2)
Atomic radius: 162
Density: 4.472 g/cm³

Configuration: [Kr] 4d1 5s2

Electron Affinity: -30

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40 Zirconium - transition metal

Melts at 2128°K or 1855°C
Boils at 4682°K or 4409°C

Discovered: 1789

Atomic mass: 91.224(2)
Atomic radius: 148
Density: 6.511 g/cm³

Configuration: [Kr] 4d2 5s2

Electron Affinity: -41

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41 Niobium - transition metal

Melts at 2750°K or 2477°C
Boils at 5017°K or 4744°C

Discovered: 1801

Atomic mass: 92.90638(2)
Atomic radius: 137
Density: 8.57 g/cm³

Configuration: [Kr] 4d4 5s1

Electron Affinity: -86

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42 Molybdenum - transition metal

Melts at 2896°K or 2623°C
Boils at 4912°K or 4639°C

Discovered: 1778

Atomic mass: 95.96(2)
Atomic radius: 145
Density: 10.28 g/cm³

Configuration: [Kr] 4d5 5s1

Electron Affinity: -72

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43 Technetium - transition metal

Not found on Earth Technetium was synthesized in a lab.

Melts at 2430°K or 2157°C
Boils at 4538°K or 4265°C

Discovered: 1937

Atomic mass: 98
Atomic radius: 156
Density: 11.5 g/cm³

Configuration: [Kr] 4d5 5s2

Electron Affinity: -53

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44 Ruthenium - transition metal

Ruthenium is the first of the six platinum group of metals and one of the noble metals. Noble metals are extremely resistant to corrosion and found in nature in their pure form. The most basic list includes all the platinum group: ruthenium, rhodium, palladium, osmium, iridium and platinum plus gold. In some contexts the list is expanded to include silver, copper and mercury.

It is not widely used industrially, although it is found in some catalysts and alloys. It is more useful in the chemistry laboratory, where it has helped several chemists win Nobel Prizes.

It has the highest oxidation state of any element at 8, shared with xenon and osmium.

It’s found as a by product of nickel mining. It’s been used in fountain pen nibs.

Melts at 2607°K or 2334°C
Boils at 4423°K or 4150°C

Discovered: 1827

Atomic mass: 101.07(2)
Atomic radius: 126
Density: 12.37 g/cm³

Configuration: [Kr] 4d7 5s1

Electron Affinity: -101

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45 Rhodium - transition metal

The most expensive metal on earth. Rhodium is extremely reflective, rivalling that of chrome.

Melts at 2237°K or 1964°C
Boils at 3968°K or 3695°C

Discovered: 1803

Atomic mass: 102.90550(2)
Atomic radius: 135
Density: 12.45 g/cm³

Configuration: [Kr] 4d8 5s1

Electron Affinity: -110

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46 Palladium - transition metal

Melts at 1828°K or 1555°C
Boils at 3236°K or 2963°C

Discovered: 1803

Atomic mass: 106.42(1)
Atomic radius: 131
Density: 12.023 g/cm³

Configuration: [Kr] 4d10

Electron Affinity: -54

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47 Silver - transition metal

Melts at 1235°K or 962°C
Boils at 2435°K or 2162°C

Discovered: antiquity

Atomic mass: 107.8682(2)
Atomic radius: 153
Density: 10.49 g/cm³

Configuration: [Kr] 4d10 5s1

Electron Affinity: -126

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48 Cadmium - transition metal

Melts at 594°K or 321°C
Boils at 1040°K or 767°C

Discovered: 1817

Atomic mass: 112.411(8)
Atomic radius: 148
Density: 8.65 g/cm³

Configuration: [Kr] 4d10 5s2

Electron Affinity: 0

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49 Indium - metal

Indium is a silvery metal that is soft and malleable. The metal is stable in air and water. However, it can dissolve in acids. It has a melting point is 156 °C (313.88 F) and its boiling point is 2000 °C (3,761.6 F). When indium is exposed to temperatures higher than its melting point it bursts into violet-colored flames.

Melts at 430°K or 157°C
Boils at 2345°K or 2072°C

Discovered: 1863

Atomic mass: 114.818(3)
Atomic radius: 144
Density: 7.31 g/cm³

Configuration: [Kr] 4d10 5s2 5p1

Electron Affinity: -29

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50 Tin - metal

Melts at 505°K or 232°C
Boils at 2875°K or 2602°C

Discovered: antiquity

Atomic mass: 118.710(7)
Atomic radius: 141
Density: 7.31 g/cm³

Configuration: [Kr] 4d10 5s2 5p2

Electron Affinity: -107

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51 Antimony - metalloid

Melts at 904°K or 631°C
Boils at 1860°K or 1587°C

Discovered: antiquity

Atomic mass: 121.760(1)
Atomic radius: 138
Density: 6.697 g/cm³

Configuration: [Kr] 4d10 5s2 5p3

Electron Affinity: -103

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52 Tellurium - metalloid

Melts at 723°K or 450°C
Boils at 1261°K or 988°C

Discovered: 1782

Atomic mass: 127.60(3)
Atomic radius: 135
Density: 6.24 g/cm³

Configuration: [Kr] 4d10 5s2 5p4

Electron Affinity: -190

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53 Iodine - halogen

Iodine is the heaviest stable element in the halogen group.

The thyroid gland uses iodine to make the hormones thyroxine and triiodotyronine. Insufficient iodine leads to development of a goiter, which is a swelling of the thyroid gland. Iodine deficiency is believed to be the leading preventable cause of mental retardation. Excessive iodine symptoms are similar to those of iodine insufficiency. Iodine toxicity is more severe if a person has a selenium deficiency.

Natural food sources of iodine are seafood, kelp and plants grown in iodine-rich soil. Potassium iodide often is added to table salt to produce iodized salt.

Commercially, iodine is mined in Chile and extracted from iodine-rich brine, notably from the oilfields in the US and Japan. Prior to this, iodine was extracted from kelp.

Melts at 387°K or 114°C
Boils at 457°K or 184°C

Discovered: 1811

Atomic mass: 126.90447(3)
Atomic radius: 133
Density: 4.94 g/cm³

Configuration: [Kr] 4d10 5s2 5p5

Electron Affinity: -295

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54 Xenon - noble gas

Melts at 161°K or -112°C
Boils at 165°K or -108°C

Discovered: 1898

Atomic mass: 131.293(6)
Atomic radius: 130
Density: 0.0059 g/cm³

Configuration: [Kr] 4d10 5s2 5p6

Electron Affinity: 0

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55 Caesium - alkali metal

Caesium is so reactive it’s stored in sealed glass bottles containing only argon gas.

Melts at 302°K or 29°C
Boils at 944°K or 671°C

Discovered: 1860

Atomic mass: 132.9054519(2)
Atomic radius: 225
Density: 1.879 g/cm³

Configuration: [Xe] 6s1

Electron Affinity: -46

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56 Barium - alkaline earth metal

Melts at 1000°K or 727°C
Boils at 2143°K or 1870°C

Discovered: 1808

Atomic mass: 137.327(7)
Atomic radius: 198
Density: 3.51 g/cm³

Configuration: [Xe] 6s2

Electron Affinity: -14

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-

Melts at °K or
Boils at °K or

Discovered:

Atomic mass:
Atomic radius:
Density: g/cm³

Configuration:

Electron Affinity:

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- lanthanoid

Melts at °K or
Boils at °K or

Discovered:

Atomic mass:
Atomic radius:
Density: g/cm³

Configuration:

Electron Affinity:

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57 Lanthanum - lanthanoid

Lanthanum means ’to hide’ and was hidden inside cerium oxide sample for 36 years before it was separated.

It’s the first element of the lanthanides giving it’s name to the group. But there is controversy about whether it is really a lanthanide at all with some claiming it is transition metal. There is also controversy about the group name lanthanide too. In 1985 the IUPAC said that the group should be called lanthanoids rather than lanthanides.

The lanthanides and actinides together comprise the ‘rare earths’ and so lanthanum is the first of these. But again it’s not particularly rare at all. There is 4 times as much lanthanum as there is lead.

Lanthanum is silvery white, malleable, ductile, and soft enough to be cut with a knife. It is one of the most reactive of the rare-earth metals. It oxidizes rapidly when exposed to air. Cold water attacks lanthanum slowly, while hot water attacks it much more rapidly.

Melts at 1193°K or 920°C
Boils at 3737°K or 3464°C

Discovered: 1839

Atomic mass: 138.90547(7)
Atomic radius: 169
Density: 6.146 g/cm³

Configuration: [Xe] 5d1 6s2

Electron Affinity: -48

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58 Cerium - lanthanoid

Melts at 1071°K or 798°C
Boils at 3633°K or 3360°C

Discovered: 1803

Atomic mass: 140.116(1)
Atomic radius:
Density: 6.689 g/cm³

Configuration: [Xe] 4f1 5d1 6s2

Electron Affinity: -50

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59 Praseodymium - lanthanoid

Melts at 1204°K or 931°C
Boils at 3563°K or 3290°C

Discovered: 1885

Atomic mass: 140.90765(2)
Atomic radius:
Density: 6.64 g/cm³

Configuration: [Xe] 4f3 6s2

Electron Affinity: -50

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60 Neodymium - lanthanoid

Melts at 1294°K or 1021°C
Boils at 3373°K or 3100°C

Discovered: 1885

Atomic mass: 144.242(3)
Atomic radius:
Density: 7.01 g/cm³

Configuration: [Xe] 4f4 6s2

Electron Affinity: -50

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61 Promethium - lanthanoid

Takes its name from Prometheus, the god who stole fire from heaven and gave it to human beings only to be punished for this act by Zeus. The connection of this tale to element 61 is in the heroic effort that was needed to isolate it, by analogy to the heroic and dangerous feat of Prometheus in Greek mythology. Promethium is one of the few elements that do not occur naturally on the earth. It was obtained as a decay product from the fission of another element, uranium.

Melts at 1373°K or 1100°C
Boils at 3273°K or 3000°C

Discovered: 1947

Atomic mass: 145
Atomic radius:
Density: 7.264 g/cm³

Configuration: [Xe] 4f5 6s2

Electron Affinity: -50

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62 Samarium - lanthanoid

Melts at 1345°K or 1072°C
Boils at 2076°K or 1803°C

Discovered: 1853

Atomic mass: 150.36(2)
Atomic radius:
Density: 7.353 g/cm³

Configuration: [Xe] 4f6 6s2

Electron Affinity: -50

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63 Europium - lanthanoid

Melts at 1095°K or 822°C
Boils at 1800°K or 1527°C

Discovered: 1901

Atomic mass: 151.964(1)
Atomic radius:
Density: 5.244 g/cm³

Configuration: [Xe] 4f7 6s2

Electron Affinity: -50

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64 Gadolinium - lanthanoid

Melts at 1586°K or 1313°C
Boils at 3523°K or 3250°C

Discovered: 1880

Atomic mass: 157.25(3)
Atomic radius:
Density: 7.901 g/cm³

Configuration: [Xe] 4f7 5d1 6s2

Electron Affinity: -50

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65 Terbium - lanthanoid

Melts at 1629°K or 1356°C
Boils at 3503°K or 3230°C

Discovered: 1843

Atomic mass: 158.92535(2)
Atomic radius:
Density: 8.219 g/cm³

Configuration: [Xe] 4f9 6s2

Electron Affinity: -50

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66 Dysprosium - lanthanoid

Melts at 1685°K or 1412°C
Boils at 2840°K or 2567°C

Discovered: 1886

Atomic mass: 162.500(1)
Atomic radius:
Density: 8.551 g/cm³

Configuration: [Xe] 4f10 6s2

Electron Affinity: -50

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67 Holmium - lanthanoid

Melts at 1747°K or 1474°C
Boils at 2973°K or 2700°C

Discovered: 1878

Atomic mass: 164.93032(2)
Atomic radius:
Density: 8.795 g/cm³

Configuration: [Xe] 4f11 6s2

Electron Affinity: -50

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68 Erbium - lanthanoid

Melts at 1770°K or 1497°C
Boils at 3141°K or 2868°C

Discovered: 1842

Atomic mass: 167.259(3)
Atomic radius:
Density: 9.066 g/cm³

Configuration: [Xe] 4f12 6s2

Electron Affinity: -50

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69 Thulium - lanthanoid

Melts at 1818°K or 1545°C
Boils at 2223°K or 1950°C

Discovered: 1879

Atomic mass: 168.93421(2)
Atomic radius:
Density: 9.321 g/cm³

Configuration: [Xe] 4f13 6s2

Electron Affinity: -50

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70 Ytterbium - lanthanoid

Melts at 1092°K or 819°C
Boils at 1469°K or 1196°C

Discovered: 1878

Atomic mass: 173.054(5)
Atomic radius:
Density: 6.57 g/cm³

Configuration: [Xe] 4f14 6s2

Electron Affinity: -50

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71 Lutetium - lanthanoid

Melts at 1936°K or 1663°C
Boils at 3675°K or 3402°C

Discovered: 1907

Atomic mass: 174.9668(1)
Atomic radius: 160
Density: 9.841 g/cm³

Configuration: [Xe] 4f14 5d1 6s2

Electron Affinity: -50

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72 Hafnium - transition metal

Melts at 2506°K or 2233°C
Boils at 4876°K or 4603°C

Discovered: 1923

Atomic mass: 178.49(2)
Atomic radius: 150
Density: 13.31 g/cm³

Configuration: [Xe] 4f14 5d2 6s2

Electron Affinity: 0

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73 Tantalum - transition metal

Melts at 3290°K or 3017°C
Boils at 5731°K or 5458°C

Discovered: 1802

Atomic mass: 180.94788(2)
Atomic radius: 138
Density: 16.65 g/cm³

Configuration: [Xe] 4f14 5d3 6s2

Electron Affinity: -31

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74 Tungsten - transition metal

Tungsten’s symbol is W after the German name for the element wolfram.

It has the second highest melting point at 3422°C after carbon (3550°C) and the second highest boiling point after its neighbour Rhenium.

Melts at 3695°K or 3422°C
Boils at 5828°K or 5555°C

Discovered: 1783

Atomic mass: 183.84(1)
Atomic radius: 146
Density: 19.25 g/cm³

Configuration: [Xe] 4f14 5d4 6s2

Electron Affinity: -79

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75 Rhenium - transition metal

Rhenium the last non radio active element to have been discovered - maybe. One isotope is radioactive (half life is 65bn years). Ogawa in 1908.

Rhenium has the highest boiling point of all the elements. The the fourth highest melting point and third most dense element.

Melts at 3459°K or 3186°C
Boils at 5869°K or 5596°C

Discovered: 1925

Atomic mass: 186.207(1)
Atomic radius: 159
Density: 21.02 g/cm³

Configuration: [Xe] 4f14 5d5 6s2

Electron Affinity: -15

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76 Osmium - transition metal

Osmium is the hardest metal element. It’s also the densest element.

Melts at 3306°K or 3033°C
Boils at 5285°K or 5012°C

Discovered: 1803

Atomic mass: 190.23(3)
Atomic radius: 128
Density: 22.61 g/cm³

Configuration: [Xe] 4f14 5d6 6s2

Electron Affinity: -106

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77 Iridium - transition metal

Iridium is shiny, dense metal that is about 40 times rarer than gold and twice the density of lead. In fact it’s the second densest element, only slightly less dense than it’s neighbour Osmium. It’s unreactive and won’t oxidize in air up to about 2000C and won’t react in acid. It’s the most corrosive resistant metal. It will react in fluorine though as long as the temperature is at least 600C.

Although rare on earth it is much more common on asteroids.

A thin layer of iridium covering the earth was found by geologists dating to around 66 million years ago. This marks the KT boundary: the end of the cretacious and start of the palogene period. This is thought to have come from an asteroid about 10km across that hit the earth and wiped out the dinosaurs.

The salts of iridium come in many different colours and this is where its name comes from: it’s named after Iris, the Greek goddess of the rainbow.

It was used in fountain pen nibs alloyed with gold. Nowadays you may still see fountain pens advertised with iridium even though there maybe no iridium used in their production.

Melts at 2739°K or 2466°C
Boils at 4701°K or 4428°C

Discovered: 1803

Atomic mass: 192.217(3)
Atomic radius: 137
Density: 22.65 g/cm³

Configuration: [Xe] 4f14 5d7 6s2

Electron Affinity: -151

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78 Platinum - transition metal

Melts at 2041°K or 1768°C
Boils at 4098°K or 3825°C

Discovered: antiquity

Atomic mass: 195.084(9)
Atomic radius: 128
Density: 21.09 g/cm³

Configuration: [Xe] 4f14 5d9 6s1

Electron Affinity: -205

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79 Gold - transition metal

The symbol for gold, Au, comes from the latin word aurum which means yellow.

Gold has been collected by humans since the Paleolithic period, 40,000BCE. The oldest known gold coins date back to 600BCE in Lydia (now Turkey).

Gold is the most malleable metal. A gram of gold, about a grain sized piece, of gold can be beaten into a sheet 1 metre square. It’s also highly ductile (stretchy). 28 grams of gold can be stretched out to make a wire that is 80km long.

Gold is relatively unreactive and one of the noble metals. The noble metals are corrosion resistant and usually found in their raw form in nature. The largest gold nugget ever found is the ‘Welcome Stranger’ found in Victoria, Australia in 1869. This weighed more than 70kg.

Even nitric acid won’t disolve gold. The term ‘acid test’ comes from testing gold with nitric acid to test whether it is the real thing. Gold can be disolved in aqua regia though, a mix of nitric and hydrochloric acids. This technique was employed in Copenhagen during World War 2 to successfully hide two Nobel prize medals from the invading Nazis.

Melts at 1337°K or 1064°C
Boils at 3129°K or 2856°C

Discovered: antiquity

Atomic mass: 196.966569(4)
Atomic radius: 144
Density: 19.3 g/cm³

Configuration: [Xe] 4f14 5d10 6s1

Electron Affinity: -223

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80 Mercury - transition metal

Melts at 234°K or -39°C
Boils at 630°K or 357°C

Discovered: antiquity

Atomic mass: 200.59(2)
Atomic radius: 149
Density: 13.534 g/cm³

Configuration: [Xe] 4f14 5d10 6s2

Electron Affinity: 0

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81 Thallium - metal

Melts at 577°K or 304°C
Boils at 1746°K or 1473°C

Discovered: 1861

Atomic mass: 204.3833(2)
Atomic radius: 148
Density: 11.85 g/cm³

Configuration: [Xe] 4f14 5d10 6s2 6p1

Electron Affinity: -19

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82 Lead - metal

The symbol Pb derives from the latin word plumbum for lead and this is where the word plumbers comes from.

Melts at 601°K or 328°C
Boils at 2022°K or 1749°C

Discovered: antiquity

Atomic mass: 207.2(1)
Atomic radius: 147
Density: 11.34 g/cm³

Configuration: [Xe] 4f14 5d10 6s2 6p2

Electron Affinity: -35

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83 Bismuth - metal

Bismuth forms labyrinthine square crystals, which glisten like oil on a puddle. Bismuth has become a favorite desktop ornament and decorative knickknack for mineralogists and element nuts because it can form rocks known as hopper crystals, which twist themselves into elaborate rainbow staircases.

Bismuth is one of the very few chemicals that expands when it freezes. It’s a fairly dense metal, denser than iron and slightly less dense than lead.

Bismuth was thought to have only one stable isotope: bismuth 209. This isotope makes up 100% of the bismuth found today.

It was only found to be radioactive in 2003. 10kg of bismuth emits one alpha particle every 25s. This is an extremely slow rate. It’s half life is 20 quintillion years or 20 billion billion years. 2.01 x 10^19. This over a billion times the age of the universe.

Melts at 544°K or 271°C
Boils at 1837°K or 1564°C

Discovered: antiquity

Atomic mass: 208.98040(1)
Atomic radius: 146
Density: 9.78 g/cm³

Configuration: [Xe] 4f14 5d10 6s2 6p3

Electron Affinity: -91

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84 Polonium - metalloid

One gram of polonium 210 emits as many alpha particles as five kilograms of radium. The element is 250-thousand times more toxic than cyanide. So, one gram of Po-210, if ingested or injected, could kill 10 million people. As it emits only alpha particles it’s hard to detect and so easy to smuggle through detectors.

Polonium is a very rare natural element. It is found in uranium ores but it is uneconomical to extract it. It is obtained by bombarding bismuth-209 with neutrons to give bismuth-210, which then decays to form polonium. All the commercially produced polonium in the world is made in Russia.

Russian dissident Alexander Litvinenko was murdered with Polonium whilst residing in the UK in 2006.

Tobacco smoke contains polonium-210. This comes not from the tobacco plant itself but the high phosphate fertilizers used in production.

Polonium-209 is more stable with a half life of 128 years.

Melts at 527°K or 254°C
Boils at 1235°K or 962°C

Discovered: 1898

Atomic mass: 209
Atomic radius:
Density: 9.196 g/cm³

Configuration: [Xe] 4f14 5d10 6s2 6p4

Electron Affinity: -183

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85 Astatine - halogen

Melts at 575°K or 302°C
Boils at °K or

Discovered: 1940

Atomic mass: 210
Atomic radius:
Density: g/cm³

Configuration: [Xe] 4f14 5d10 6s2 6p5

Electron Affinity: -270

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86 Radon - noble gas

Melts at 202°K or -71°C
Boils at 211°K or -62°C

Discovered: 1900

Atomic mass: 222
Atomic radius: 145
Density: 0.00973 g/cm³

Configuration: [Xe] 4f14 5d10 6s2 6p6

Electron Affinity:

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87 Francium - alkali metal

Only about 1 ounce (20-30 grams) of francium can be found in the entire Earth’s crust. The amount of the element that has been synthesized by mankind isn’t even enough to weigh.

Francium is extremely dangerous being both highly reactive and radioactive.

Melts at °K or
Boils at °K or

Discovered: 1939

Atomic mass: 223
Atomic radius:
Density: g/cm³

Configuration: [Rn] 7s1

Electron Affinity:

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88 Radium - alkaline earth metal

Melts at 973°K or 700°C
Boils at 2010°K or 1737°C

Discovered: 1898

Atomic mass: 226
Atomic radius:
Density: 5 g/cm³

Configuration: [Rn] 7s2

Electron Affinity:

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-

Melts at °K or
Boils at °K or

Discovered:

Atomic mass:
Atomic radius:
Density: g/cm³

Configuration:

Electron Affinity:

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- actinoid

Highly radioactive it was once used in health products such as face creams, perfumes and radium suppositories.

Melts at °K or
Boils at °K or

Discovered:

Atomic mass:
Atomic radius:
Density: g/cm³

Configuration:

Electron Affinity:

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89 Actinium - actinoid

Melts at 1323°K or 1050°C
Boils at 3473°K or 3200°C

Discovered: 1899

Atomic mass: 227
Atomic radius:
Density: 10.07 g/cm³

Configuration: [Rn] 6d1 7s2

Electron Affinity:

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90 Thorium - actinoid

The most abundant radioactive element on earth. It’s half life is 14 billion years. Thorium is thought to be created in neutron star mergers known as kilonovas.

Melts at 2023°K or 1750°C
Boils at 5093°K or 4820°C

Discovered: 1828

Atomic mass: 232.03806(2)
Atomic radius:
Density: 11.724 g/cm³

Configuration: [Rn] 6d2 7s2

Electron Affinity:

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91 Protactinium - actinoid

Melts at 1845°K or 1572°C
Boils at 4273°K or 4000°C

Discovered: 1913

Atomic mass: 231.03588(2)
Atomic radius:
Density: 15.37 g/cm³

Configuration: [Rn] 5f2 6d1 7s2

Electron Affinity:

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92 Uranium - actinoid

Melts at 1408°K or 1135°C
Boils at 4200°K or 3927°C

Discovered: 1789

Atomic mass: 238.02891(3)
Atomic radius:
Density: 19.05 g/cm³

Configuration: [Rn] 5f3 6d1 7s2

Electron Affinity:

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93 Neptunium - actinoid

Melts at 917°K or 644°C
Boils at 4273°K or 4000°C

Discovered: 1940

Atomic mass: 237
Atomic radius:
Density: 20.45 g/cm³

Configuration: [Rn] 5f4 6d1 7s2

Electron Affinity:

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94 Plutonium - actinoid

Used to create the first atomic bomb.

Plutonium is pyrophoric, which means it tends to smolder in the air.

It can heat up to 600C as a result of radioactive decay and can be used in space thermoelectric power sources such as the Mars rovers Curiosity and Perseverance.

Melts at 913°K or 640°C
Boils at 3503°K or 3230°C

Discovered: 1940

Atomic mass: 244
Atomic radius:
Density: 19.816 g/cm³

Configuration: [Rn] 5f6 7s2

Electron Affinity:

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95 Americium - actinoid

Melts at 1449°K or 1176°C
Boils at 2284°K or 2011°C

Discovered: 1944

Atomic mass: 243
Atomic radius:
Density: g/cm³

Configuration: [Rn] 5f7 7s2

Electron Affinity:

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96 Curium - actinoid

Melts at 1618°K or 1345°C
Boils at 3383°K or 3110°C

Discovered: 1944

Atomic mass: 247
Atomic radius:
Density: 13.51 g/cm³

Configuration: [Rn] 5f7 6d1 7s2

Electron Affinity:

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97 Berkelium - actinoid

Melts at 1323°K or 1050°C
Boils at °K or

Discovered: 1949

Atomic mass: 247
Atomic radius:
Density: 14.78 g/cm³

Configuration: [Rn] 5f9 7s2

Electron Affinity:

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98 Californium - actinoid

Perhaps the most expensive element it is hard to make, is extremely dangerous and is made from weapons grade plutonium. The cost about $70m per gram.

Melts at 1173°K or 900°C
Boils at °K or

Discovered: 1950

Atomic mass: 251
Atomic radius:
Density: 15.1 g/cm³

Configuration: [Rn] 5f10 7s2

Electron Affinity:

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99 Einsteinium - actinoid

Melts at 1133°K or 860°C
Boils at °K or

Discovered: 1952

Atomic mass: 252
Atomic radius:
Density: g/cm³

Configuration: [Rn] 5f11 7s2

Electron Affinity:

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100 Fermium - actinoid

Melts at 1800°K or 1527°C
Boils at °K or

Discovered: 1952

Atomic mass: 257
Atomic radius:
Density: 9.7 g/cm³

Configuration: [Rn] 5f12 7s2

Electron Affinity:

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101 Mendelevium - actinoid

Melts at 1100°K or 827°C
Boils at °K or

Discovered: 1955

Atomic mass: 258
Atomic radius:
Density: g/cm³

Configuration: [Rn] 5f13 7s2

Electron Affinity:

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102 Nobelium - actinoid

Melts at 1100°K or 827°C
Boils at °K or

Discovered: 1957

Atomic mass: 259
Atomic radius:
Density: 9.9 g/cm³

Configuration: [Rn] 5f14 7s2

Electron Affinity:

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103 Lawrencium - actinoid

Melts at 1900°K or 1627°C
Boils at °K or

Discovered: 1961

Atomic mass: 262
Atomic radius:
Density: 14.4 g/cm³

Configuration: [Rn] 5f14 7s2 7p1

Electron Affinity:

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104 Rutherfordium - transition metal

Melts at 2400°K or 2127°C
Boils at 5800°K or 5527°C

Discovered: 1969

Atomic mass: 267
Atomic radius: 150
Density: 17 g/cm³

Configuration: [Rn] 5f14 6d2 7s2

Electron Affinity:

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105 Dubnium - transition metal

Melts at °K or
Boils at °K or

Discovered: 1967

Atomic mass: 268
Atomic radius: 139
Density: g/cm³

Configuration: [Rn] 5f14 6d3 7s2

Electron Affinity:

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106 Seaborgium - transition metal

Melts at °K or
Boils at °K or

Discovered: 1974

Atomic mass: 271
Atomic radius: 132
Density: 23 g/cm³

Configuration: [Rn] 5f14 6d4 7s2

Electron Affinity:

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107 Bohrium - transition metal

Melts at °K or
Boils at °K or

Discovered: 1976

Atomic mass: 272
Atomic radius: 128
Density: 26 g/cm³

Configuration: [Rn] 5f14 6d5 7s2

Electron Affinity:

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108 Hassium - transition metal

Melts at °K or
Boils at °K or

Discovered: 1984

Atomic mass: 270
Atomic radius: 126
Density: 28 g/cm³

Configuration: [Rn] 5f14 6d6 7s2

Electron Affinity:

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109 Meitnerium - transition metal

Meitnerium is the only element named after a woman: Lise Meitner. Curium, element 96, is named after the Polish couple Pierre and Marie Curie.

Meitner was an Austrian, and later Swedish, nuclear physicist who was instrumental in the discovery of nuclear fission. She was nominated for a Nobel prize in physics and chemistry 49 times by luminaries including Max Plank and Niels Bohr. But she never won, mostly because she was a woman.

Meitnerium is a synthetic element with a half life of only 4.5 seconds.

Melts at °K or
Boils at °K or

Discovered: 1982

Atomic mass: 276
Atomic radius: 128
Density: g/cm³

Configuration: [Rn] 5f14 6d7 7s2

Electron Affinity:

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110 Darmstadtium - transition metal

Melts at °K or
Boils at °K or

Discovered: 1994

Atomic mass: 281
Atomic radius: 132
Density: g/cm³

Configuration: [Rn] 5f14 6d9 7s1

Electron Affinity:

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111 Roentgenium - transition metal

Melts at °K or
Boils at °K or

Discovered: 1994

Atomic mass: 280
Atomic radius: 114
Density: g/cm³

Configuration: [Rn] 5f14 6d10 7s1

Electron Affinity:

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112 Copernicium - transition metal

Melts at 283°K or 10°C
Boils at 340°K or 67°C

Discovered: 1996

Atomic mass: 285
Atomic radius: 147
Density: g/cm³

Configuration: [Rn] 5f14 6d10 7s2

Electron Affinity:

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113 Nihonium - post-transition metal

Melts at 700°K or 427°C
Boils at 1430°K or 1157°C

Discovered: 2003

Atomic mass: 284
Atomic radius: 170
Density: g/cm³

Configuration: [Rn] 5f14 6d10 7s2 7p1

Electron Affinity:

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114 Flerovium - post-transition metal

Melts at 284°K or 11°C
Boils at °K or

Discovered: 1998

Atomic mass: 289
Atomic radius: 180
Density: g/cm³

Configuration: [Rn] 5f14 6d10 7s2 7p2

Electron Affinity:

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115 Moscovium - post-transition metal

Melts at 670°K or 397°C
Boils at 1400°K or 1127°C

Discovered: 2003

Atomic mass: 288
Atomic radius: 187
Density: g/cm³

Configuration: [Rn] 5f14 6d10 7s2 7p3

Electron Affinity:

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116 Livermorium - post-transition metal

Melts at 708.5°K or 435.5°C
Boils at 1085°K or 812°C

Discovered: 2000

Atomic mass: 293
Atomic radius: 183
Density: 12.9 g/cm³

Configuration: [Rn] 5f14 6d10 7s2 7p4

Electron Affinity:

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117 Tennessine - post-transition metal

Melts at 723°K or 450°C
Boils at 882°K or 609°C

Discovered: 2010

Atomic mass: 294
Atomic radius: 138
Density: 7.2 g/cm³

Configuration: [Rn] 5f14 6d10 7s2 7p5

Electron Affinity:

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118 Oganesson - noble gas

With the current highest atomic number it’s a record it could hold for some time to come. Work on elements 119 and 120 was apparently going well in a collaboration between Russian and US scientists. But this fell apart after the Russian invasion of Ukraine.

Oganesson was synthesised at the Joint Institute for Nuclear Research in Russia in 2002. Not that much is known about it. Only 5 or 6 atoms were produced and with a half life of 0.69 milliseconds it wasn’t around for very long.

It’s named after Russian nuclear physicist Yuri Oganesson, an expert on super heavy metals.

Melts at 325°K or 52°C
Boils at 450°K or 177°C

Discovered: 2002

Atomic mass: 294
Atomic radius: 152
Density: 7.2 g/cm³

Configuration: [Rn] 5f14 6d10 7s2 7p6

Electron Affinity:

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